变学习速率在线ICA算法在雷达信号分选中的应用

已有的独立分量分析(ICA)雷达分选方法多采用FastICA算法,FastICA算法是一种离线批处理ICA算法,缺乏实时分选能力.文中将一种变学习速率的在线ICA算法应用到雷达分选中,克服了FastICA算法无法实现在线实时分选的缺点;同时,算法能根据相依性测度所反映的信号分离的状态自适应地调节学习速率,平衡了传统在线ICA算法收敛速度和稳态误差之间的矛盾,从而使得采用这种ICA算法的雷达信号分选方法具有收敛速度快,分离效果好的特点.仿真实验验证了分选方法的有效性.     

Functional logistic regression: a comparison of three methods

Functional logistic regression is becoming more popular as there are many situations where we are interested in the relation between functional covariates (as input) and a binary response (as output). Several approaches have been advocated, and this paper goes into detail about three of them: dimension reduction via functional principal component analysis, penalized functional regression, and wavelet expansions in combination with Least Absolute Shrinking and Selection Operator penalization. We discuss the performance of the three methods on simulated data and also apply the methods to data regarding lameness detection for horses. Emphasis is on classification performance, but we also discuss estimation of the unknown parameter function.     

Uncertainty Quantification in Case of Imperfect Models: A Non‐Bayesian Approach

The starting point in uncertainty quantification is a stochastic model, which is fitted to a technical system in a suitable way, and prediction of uncertainty is carried out within this stochastic model. In any application, such a model will not be perfect, so any uncertainty quantification from such a model has to take into account the inadequacy of the model. In this paper, we rigorously show how the observed data of the technical system can be used to build a conservative non‐asymptotic confidence interval on quantiles related to experiments with the technical system. The construction of this confidence interval is based on concentration inequalities and order statistics. An asymptotic bound on the length of this confidence interval is presented. Here we assume that engineers use more and more of their knowledge to build models with order of errors bounded by . The results are illustrated by applying the newly proposed approach to real and simulated data.     

An Optimal Semiparametric Method for Two‐group Classification

In the classical discriminant analysis, when two multivariate normal distributions with equal variance–covariance matrices are assumed for two groups, the classical linear discriminant function is optimal with respect to maximizing the standardized difference between the means of two groups. However, for a typical case‐control study, the distributional assumption for the case group often needs to be relaxed in practice. Komori et al. (Generalized t ‐statistic for two‐group classification. Biometrics 2015, 71: 404–416) proposed the generalized t ‐statistic to obtain a linear discriminant function, which allows for heterogeneity of case group. Their procedure has an optimality property in the class of consideration. We perform a further study of the problem and show that additional improvement is achievable. The approach we propose does not require a parametric distributional assumption on the case group. We further show that the new estimator is efficient, in that no further improvement is possible to construct the linear discriminant function more efficiently. We conduct simulation studies and real data examples to illustrate the finite sample performance and the gain that it produces in comparison with existing methods.     

China's energy inefficiency: A cross-country comparison

This paper constructs a total-factor energy technical efficiency index using the data envelopment analysis (DEA) method following the total factor productivity framework. We then compare energy technical efficiency across 156 countries from 1980 to 2007. The results show that China's energy efficiency considerably trails other countries’ although it has made significant gains within the last 28 years. Further analysis indicates that scale inefficiency rather than pure technical efficiency contributes to China's energy inefficiency.     

The size and structure of China's government debt

This paper analyzes the size and structure of China's government debt. In addition to explicit government debt, we consider three types of government contingent liabilities: local government debt, university debt, and state banks’ nonperforming loans. The size of each types of debt is estimated and the reasons for the emergence of each type of debt are analyzed. International comparisons are made and it is found that China's government debt is larger than many other developing countries. To insure fiscal sustainability and to leave rooms for future expansionary fiscal policies, the government should reduce contingent liabilities.     

The role of macroeconomic policies in the global crisis

This paper argues that the lack of timely and decisive policy action to correct domestic and external imbalances contributed crucially to the build-up of financial excesses that led to the financial crisis and the Great Recession. We focus on 2002–2007 and perform a number of counterfactual simulations to investigate two central elements of the story, namely: (a) an over-expansionary US monetary policy and the absence of effective macro-prudential supervision, which permitted a prolonged expansion of debt-financed consumer spending and (b) the choice by China and other emerging countries to pursue an export-led growth strategy supported by pegging their currencies to the US dollar, in conjunction with sluggish domestic demand in major advanced economies characterized by low potential output growth. The results of the simulations lend support to the view that if substantial, globally coordinated demand rebalancing had been undertaken early on, the macroeconomic and financial imbalances would not have accumulated to the extent that they did and the financial turmoil might have had less drastic global consequences.     

Ethical Issues in Continuing Care

No abstract available for this article.     

Sorting people out: The uses of one-dimensional classificatory schemes in a multi-dimensional world

This paper examines how people are classified as part of a labour market project aimed at establishing a process for recognizing prior learning among immigrants to Sweden in order to integrate them more quickly with the labour market and society. The paper suggests that, in Sweden, this work prioritizes procedural effectiveness over a more comprehensive understanding of the competence and qualifications of the immigrant worker. By exploring the process of classification in which cognitive structuring of the perceived world results in organizational, administrative and structural enactment, the study provides further insights into how practices of classification are a central part of organizational life. The concept of intersectionality contributes by showing how individuals are situated at the intersection of a variety of classificatory schemes, and together with classification, intersectionality points to how organizational categories are never given, but a result of bureaucratic power procedures strengthening, weakening and/or negotiating away categories used to sort people out.     

智库的科学分类与准确定位

对智库进行合理分类与准确定位是智库发展的必然。现阶段中国智库的分类标准普遍采用外部标准,并形成了独特的圈层结构和依附属性。智库分类不清、定位不明、评价缺失的不足限制了智库的质量提升。智库的分类需要以其内部因素作为分类标准,形成以研究目标和研究领域两个维度的分类体系,从而形成多样化、分层次的智库类型。未来中国智库发展的要义,在于遵循智库发展的内在规律,依托于科学分类,准确定位,更多按其内在发展机理来优化结构,提升质量,谋划发展。